<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        p {
            display: none;
        }

        .on {
            color: red;
        }
    </style>
</head>

<body>

    <div>
        <button>1</button>
        <button>2</button>
        <button>3</button>
    </div>

    <div>
        <p>111</p>
        <p>222</p>
        <p>333</p>
    </div>

    <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>

    <script>

        $('button').click(function () {
            $(this).addClass('on').siblings().removeClass('on');
            $('p').eq($(this).index()).show().siblings().hide();
        })

    </script>

</body>

</html>